Does it matter what a performer feels or thinks about while performing? To investigate the effect of performers’ focus of attention on their performances we asked eight violinists to play the same musical phrase in response to three different instructions. The first instruction was to focus on the technical aspects of playing. The second instruction was to give an expressive performance. Following a sadness-inducing mood induction task, the third instruction was to play while focusing on felt emotions. High quality audio and three-dimensional motion-capture recordings were made of all performances. Subsequently, thirty individuals rated how much they liked each performance, how skilled they thought each performer was, and to what extent each performance was expressive of sadness. Computational analysis of the audio and motion-capture recordings revealed differences between performance conditions. Statistical analysis of the perception data revealed that individuals preferred the Expressive performances to the Technical and Emotional ones. In addition, the Expressive performances were rated as played by the most skilled performers. The Emotional performances were rated as being most expressive of sadness. The findings suggest that a performer’s focus of attention has an effect on the audio features, movement features, and perception of their performances.